cc: Add flag to disable future mask tiling.

cc/layers/picture_layer.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_LAYERS_PICTURE_LAYER_H_
 #define CC_LAYERS_PICTURE_LAYER_H_
 
 #include "base/macros.h"
 #include "cc/base/invalidation_region.h"
 #include "cc/debug/devtools_instrumentation.h"
@@ skipping 16 matching lines @@
   bool nearest_neighbor() const {
     return picture_layer_inputs_.nearest_neighbor;
   }
 
   // Layer interface.
   std::unique_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl) override;
   void SetLayerTreeHost(LayerTreeHost* host) override;
   void PushPropertiesTo(LayerImpl* layer) override;
   void SetNeedsDisplayRect(const gfx::Rect& layer_rect) override;
   bool Update() override;
-  void SetLayerMaskType(Layer::LayerMaskType mask_type) override;
+  void SetLayerMaskType(LayerMaskType mask_type) override;
   sk_sp<SkPicture> GetPicture() const override;
 
   bool IsSuitableForGpuRasterization() const override;
 
   void RunMicroBenchmark(MicroBenchmark* benchmark) override;
 
   ContentLayerClient* client() { return picture_layer_inputs_.client; }
 
   RecordingSource* GetRecordingSourceForTesting() {
     return recording_source_.get();
@@ skipping 15 matching lines @@
   };
 
   explicit PictureLayer(ContentLayerClient* client);
   // Allow tests to inject a recording source.
   PictureLayer(ContentLayerClient* client,
                std::unique_ptr<RecordingSource> source);
   ~PictureLayer() override;
 
   bool HasDrawableContent() const override;
 
-  Layer::LayerMaskType mask_type() { return mask_type_; }
+  LayerMaskType mask_type() { return mask_type_; }
 
   PictureLayerInputs picture_layer_inputs_;
 
  private:
   friend class TestSerializationPictureLayer;
 
   void DropRecordingSourceContentIfInvalid();
 
   std::unique_ptr<RecordingSource> recording_source_;
   devtools_instrumentation::
       ScopedLayerObjectTracker instrumentation_object_tracker_;
 
   Region last_updated_invalidation_;
 
   int update_source_frame_number_;
-  Layer::LayerMaskType mask_type_;
+  LayerMaskType mask_type_;
 
   DISALLOW_COPY_AND_ASSIGN(PictureLayer);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_PICTURE_LAYER_H_